Adding a granny flat or building a dual occupancy has become a popular way to increase rental income or house family members. In NSW, secondary dwellings of up to 60 square metres can often be approved through a faster complying development pathway, subject to the site meeting the requirements. But financing them takes some planning.
Granny flat vs dual occupancy
Granny flat (secondary dwelling): a smaller self-contained dwelling on the same lot as your main home. It usually can't be subdivided or sold separately.
Dual occupancy: two dwellings on one lot, such as a duplex. Depending on zoning and council approval, it may be possible to strata or Torrens title and sell them separately.
Ways to finance a granny flat
Use equity in your home
If you have enough equity, you can add a loan split or refinance to release funds. For larger builds, lenders may require a construction loan with progress payments.
Construction loan
A construction loan releases money in stages as the builder completes work. Lenders want a fixed-price building contract, plans and approvals.
Builder finance
Some granny flat builders offer finance packages. Compare these carefully against standard lending, as rates and fees may be higher.
How lenders value granny flats
This is the tricky part. A granny flat costing $180,000 to build won't necessarily add $180,000 to the property's value. Valuers consider:
- The value of the overall property with the secondary dwelling
- Local demand for properties with granny flats
- Quality and approval status
Some lenders will value "as if complete" and lend against the improved value; others won't.
Rental income and serviceability
Many lenders will count rental income from a granny flat, often at a shaded rate. Some lenders require a lease or rental appraisal. Policies vary on whether they count granny flat rent on an owner-occupied property.
Granny flat rent can significantly boost serviceability, which helps when you're borrowing to build.
Dual occupancy finance
Dual occupancy is closer to a small development. Lenders look at:
- Your experience and the project size
- Whether you'll keep or sell the dwellings
- Pre-sales or rental appraisals
- Total development costs and contingency
Larger projects may need development finance rather than standard home loans.
Tax and insurance points
- Rental income from a granny flat is generally taxable
- Renting part of your home can affect your main residence CGT exemption for that portion
- Your insurer needs to know about the second dwelling
Speak to your accountant before you build.
Frequently asked questions
Can I get a home loan to build a granny flat?
Yes, through a construction loan or by using equity. Some lenders are more comfortable with granny flats than others.
Will my bank count the granny flat rent?
Many lenders will, with a lease or rental appraisal, though often at 70% to 80%.
Can I live in the granny flat and rent the main house?
Yes, that's common. It affects your loan purpose and tax, so tell your lender and accountant.
Planning a granny flat or duplex? Call Finfident on 0424 545 654. We'll find a lender comfortable with secondary dwellings.
This article is general information only and doesn't take into account your objectives, financial situation or needs. Figures, rates and scheme rules are current as at October 2026 and can change. Finfident Finance Brokers (ABN 94 679 280 801) is Credit Representative 569374 of Outsource Financial Pty Ltd (ACN 131 090 705), Australian Credit Licence 384324.